Organochlorine and organophosphorous pesticide residues in the Ouémé River catchment in the Republic of Bénin

The Ouémé River is one of the most important rivers in the Republic of Bénin. It is 510 km long and its catchment drains 75% of the country. In this study, organochlorine and organophosphorous pesticide residues were measured in more than 35 sediment samples collected on nine locations along the Ouémé River from upstream to downstream. Except for one location, Tanéka-Koko, all areas were contaminated by more than 20 pesticides. Organochlorine pesticides identified in sediment samples included pp'-DDE, op'-DDD, pp'-DDD, op'-DDT, pp'-DDT, alpha-endosulfan, beta-endosulfan, endosulfan sulphate, alpha-HCH, beta-HCH, lindane, aldrin, dieldrin, endrin, telodrin, isodrin, cis- and trans-heptachlorepoxide, hexachlorbutadiene, hexachlorobenzene and octachlorostyrene. The organophosphorous pesticide chlorpyrifos, used in a new formulation to protect cotton, was also identified. In some areas, the concentrations of organochlorine pesticides in the sediment of the Ouémé River exceeded environmental quality standards and are reason for concern.     

Contamination of fish by organochlorine pesticide residues in the Ouémé River catchment in the Republic of Bénin

In the Republic of Bénin, aquatic ecosystems are subject to poisoning risks due to the inappropriate use of pesticides, such as washing of empty bottles in rivers and using pesticides to catch fish. In some areas, cotton fields are located near riverbanks, increasing the probability of pesticide emission to the river. To assess contamination levels in the Ouémé River catchment area, different fish species were collected from different geographical areas along the river. DDT, its metabolites and isomers were the most frequently identified pesticides in fish flesh, alpha-endosulfan, beta-endosulfan, dieldrin, telodrin, lindane and octachlorostyrene were also detected. Concentrations of pesticide residues in fish ranged from 0 to 1364 ng/g lipid. A preliminary risk assessment indicated that the daily intake of chlorinated pesticides by people consuming fish from the Ouémé River still is rather low and does not present an immediate risk.     

Coastal dune development and sand drifting management along an artificial shoreline: the case of Dunkirk harbour,northern France

Harbour development along the low-lying coastline of northern France necessitated the construction of a seaport protruding into the sea. The extension of the port of Dunkirk resulted in the creation of an artificial shoreline consisting of a sea dike fronted by a beach, connected to a jetty protecting the seaport access. This study illustrates how harbour infrastructure can give rise to new kinds of aeolian landforms: e.g. the spontaneous initiation of aeolian dunes on a seaport dike resulting in specific dune types. However, this coastal dune development induced unexpected sand invasion of harbour infrastructure. The aim of this study was to test the effectiveness of various types of windbreaks on a dike as a means of limiting sand drift and solving sand invasion problems. Seven experimental fences installed in the eastern part of the dike were monitored over an 11 month period. The experimental fences tested in this study demonstrated their effectiveness on an asphalt coated dike. Over the whole survey period, the most efficient fences were those installed close to a sand source, at the beach-dike limit. These experiments will aid the Port of Dunkirk in building a management plan for its shoreline, which is being designed in order to preserve the diversity of landscapes, and to control sand invasion which necessitates costly sand removal operations.     

Relative bioavailability of soil-bound chlordecone in growing lambs

The pollution of soil with the pesticide chlordecone (CLD) is a problem for the use of agricultural surfaces even years after its use has been forbidden. Therefore, the exposure of free-ranged animals such as ruminants needs to be investigated in order to assess the risk of contamination of the food chain. Indeed, measured concentrations could be integrated in a lowered extent if the soil binding would reduce the bioavailability of the pesticide. This bioavailability of soil-bound CLD in a heavily polluted andosol has been investigated relatively of CLD given via spiked oil. Twenty-four weaned lambs were exposed to graded doses of 2, 4 or 6 μg CLD/kg body weight during 15 days via the contaminated soil in comparison to spiked oil. The concentration of this pesticide has been determined in two target tissues: blood serum and kidney fat. The relative bioavailability (RBA) corresponds to the slope ratio between the test matrix-contaminated soil- in comparison to the reference matrix oil. The RBA of the soil-bound CLD was not found to significantly differ from the reference matrix oil in lambs meaning that the pesticide ingested by grazing ruminants would not be sequestered by soil binding. Therefore, CLD from soil gets bioavailable within the intestinal level and exposure to contaminated soil has to be integrated in risk assessments.     

Implementation of a medical command and control team in Switzerland

In case of a major incident or disaster, the advance medical rescue command needs to manage several essential tasks simultaneously. These include the rapid deployment of ambulance, police, fire and evacuation services, and their coordinated activity, as well as triage and emergency medical care on site. The structure of such a medical rescue command is crucial for the successful outcome of medical evacuation at major incidents. However, little data has been published on the nature and structure of the command itself. This study presents a flexible approach to command structure, with two command heads: one emergency physician and one experienced paramedic. This approach is especially suitable for Switzerland, whose federal system allows for different structures in each canton. This article examines the development of these structures and their efficiency, adaptability and limitations with respect to major incident response in the French‐speaking part of the country.     

Feeding grounds for waders in the Bay of the Mont Saint-Michel (France): the Lanice conchilega reef serves as an oasis in the tidal flats

The tube-building polychaete Lanice conchilega can form dense populations, often called reefs, which promote benthic community change and constitute feeding grounds for secondary consumers. The aim of this study was to quantify the role of the L. conchilega reef of the Bay of the Mont Saint-Michel (BMSM) for feeding waders, by combining macrobenthos data, bird counts and bird diet information. Wader densities in the reef were on average 46.6 times higher than in non-reef areas. According to faecal analyses, waders in the reef mainly selected the accompanying fauna and especially crustaceans. The attractiveness of the reef to feeding birds may be largely explained by the high abundance, richness and biomass of macrobenthic species in the reef compared with the rest of the BMSM.     

Identifying and mapping local bycatch hotspots of loggerhead sea turtles using a GIS-based method: implications for conservation

Fisheries bycatch of marine megafauna is a worldwide conservation issue. In this study, we propose a method for generating reliable maps of sea turtle bycatch hotspots. Based on a well-defined area of fishing effort determined from the longline sets monitored in 2007 and 2010, we calculated the fishing area with the highest turtle bycatch density for both years. Our results show that it is important to consider all the components of fishing effort (area, number of hooks and soak time) in order to standardize the bycatch events, and thus the spatial density of the captures can be considered an index of abundance and aggregation of the species. Moreover, the high-resolution level of the analyses was useful for investigating the cumulative effect of the longline sets, which often overlap, and made it possible to correctly map the capture density and the intensity of the fishing effort at any given location.     

Assessment of the aerobic preparation and bottom ash addition as pretreatment steps before landfilling: Impact on methanogenesis kinetics and leachate parameters

This work focuses on assessing the impact of two types of waste pretreatment: addition of bottom ashes and aerobic pretreatment on both the onset and kinetics of methanogenesis and the evolution of different parameters in the leachate. It also studies the correlation between methane production and the different parameters measured in the leachate produced. A total of six 68-L pilots were thus used with fresh municipal solid waste (MSW) shredded to a 40-mm size. After 14months of landfilling, the control has produced less than 10NLkg(-1)DM, which corresponds to around 7% of its biochemical methane potential (BMP). Nevertheless, on one hand for aerobically pretreated waste, the lag phase before the onset of methanogenesis is significantly reduced to 0.9month compared to more than 1year for the control. In addition to that, on average 110NLkg(-1)DM (90% of the BMP) is produced within around 6.5months. On the other hand, the waste with added bottom ash shows a slight improvement of the lag phase over the control for one of the duplicate: 6.1months of lag phase. At this stage, on average of 26NLkg(-1)DM waste are detected (22% of the BMP) no final conclusion concerning the impact of bottom ashes could be made. The data obtained for the leachate parameters agrees with the observations on methane production. Statistical correlation study shows that the two components of the corrected PCA interpret 76% of the variability of the data: SUVA (specific UV absorbance at 254nm) and HPI(*) (% of hydrophilic compounds) are identified as interesting parameters for following up the biodegradation in landfill conditions.     

An empirical investigation of returns to scale: The Welsh coal industry

This article attempts to study both returns to scale and optimal size of production. Specifically, the authors estimate a ray-homothetic production function which allows the returns to scale to vary with ouput size and input mix. The production model is estimated using data from the Welsh coal industry for the period 1961–1976. Findings showed that, first, the Welsh coal industry suffers from a level of production which is either too small or below its optimal level and, second, this discrepancy between actual and optimal production worsened over the period considered.